The instant invention relates to a document feeding device, and more particularly to a device for maintaining paper documents being fed seriatim from a hopper at their optimum pack pressure and angle for separation and feeding.
Inserting machines typically include a plurality of feeding devices which feed documents from a pack of documents situated in a hopper seriatim to a transport deck therebelow, from which a collated packet of documents are eventually inserted into an envelope. The inserter document feeders employ hoppers that generally are inclined at a fixed angle which usually is somewhere between about 20 and 30 degrees. The feeder depends on gravity to slide the documents down to and against a separator roller and stone. The nature of this system is such that it is virtually impossible to maintain an ideal pack pressure and pack angle in the documents throughout the hopper's full capacity. A full hopper creates too high a pack pressure and angle while a near empty hopper creates too low a pack pressure and angle. The nature of the material being fed may also contribute to the difficulty of maintaining the optimum pack pressure and angle depending upon whether the material is glossy or rough (finish), or whether it is curled, twisted, spongy, thick or heavy.
The foregoing problems of maintaining optimum pack pressure and angle in a pack of documents to be fed from a document feeder hopper are overcome by the instant invention which maintains the ideal pack pressure and angle regardless of the number of documents loaded into the hopper or any of the characteristics of the documents.